1. Field of the Invention
The present invention relates generally to an ultra-broadband transverse electromagnetic (TEM) exponential horn antenna, and more particularly pertains to an antenna as described wherein at the radiating or receiving end, the widths of first and second conductors expand exponentially in the H-plane, and the spacing between the first and second conductors expands exponentially in the E-plane, thereby providing a double flared, exponentially tapered, transverse electromagnetic horn antenna.
An antenna as described herein can function as either a receiving or transmitting antenna. As a transmitting antenna, an impulse function can be utilized as the transmitted waveform, which results in a theoretically infinite bandwidth for the antenna.
The design of ground based or airborne radar systems which utilize an impulse function as a transmitted waveform has recently become of interest because the frequency spectrum of an impulse waveform has a theoretically infinite bandwidth. An ultra-broad bandwidth results in a radar system with unique capabilities, such as foliage penetration at low frequency wavelengths and high target resolution achieved at high frequency wavelengths.
The key components of an impulse function radar system are the receive and transmit antennas which require the combined attributes of ultra-broadband frequency response, high gain for long range target detection, high transmit voltage stand-off necessary for handling the necessary waveform power in nanosecond time frames, and nondispersive phase properties to maintain waveform fidelity. The present invention provides a design for a novel ultra-broadband antenna designed to be used in combination with a parabolic reflector, which should provide all of the electrical properties described above.
2. Discussion of the Prior Art
The prior art has considered a similar design for a TEM horn antenna, but wherein the conductor strips forming the antenna have a linearly expanding flare, not an exponentially expanding double flared design. Moreover, the prior art antenna is also not flared in both the H-plane and the E-plane to provide a double flared design similar to that of the present invention.
The design of an infinite balun component as described herein is well known in the art, and infinite baluns have been used with spiral or helix antennas, but not with an ultra-broadband transverse electromagnetic horn antenna similar to that of the present invention.